1. Field of the Invention
The present invention relates to a vehicle suspension apparatus for reducing a roll generated in a vehicle body when a vehicle turns.
2. Description of the Related Art
For example, U.S. Pat. Nos. 3,608,925, 4,624,476, and 4,730,843 disclose a vehicle suspension apparatus comprising a fluid spring chamber provided for each wheel and inserted between the wheel and a vehicle body, a fluid supply means for supplying a fluid to the fluid spring chambers through supply valve means, a fluid means for exhausting the fluid from the fluid spring chambers through exhaust valve means, a roll amount detecting means for detecting a roll amount of the vehicle body, and a roll control means for setting a control target corresponding to the roll amount detected by the roll amount detecting means and executing roll control in which the supply valve means corresponding to the fluid spring chambers at a contracting side with respect to a direction of roll generated in the vehicle body and the exhaust valve means corresponding to the fluid spring chambers at an expanding side are opened in accordance with the control target.
However, since the weight of a front portion of a vehicle body is generally different from that of a rear portion, a roll amount generated in the front portion of the vehicle body upon a turning operation is different from that in the rear portion. Therefore, roll control is preferably performed such that a roll control amount at the front portion differs from that at the rear portion.
U.S. Pat. No. 4,673,193 discloses a suspension apparatus having hardware which can make a roll control amount at a front side different from that at a rear side. However, U.S. Pat. No. 4,673,193 does not disclose a detecting means and a control method of the suspension apparatus for making the roll control amount at the front side different from that at the rear side.